Coil Module, Array Probe, Eddy Current Testing Device

The present disclosure relates to a coil module, an array probe, and an eddy current testing device.

Priority is claimed on Japanese Patent Application No. 2022-136509 filed on Aug. 30, 2022, the content of which is incorporated herein by reference.

An eddy current testing method is known as a method for non-destructively inspecting defects such as flaws and thinning in a pipe and the like. In this method, a cross coil including an excitation coil that generates an eddy current from an inner surface to an outer surface of a pipe, a detection coil that detects a disturbance of the eddy current generated at a defective part of the pipe, and a winding frame around which the winding of the excitation coil and the winding of the detection coil are wound is generally used in the related art (for example, see PTL 1).

In order to manufacture the cross coil, a method for alternately winding the winding of the excitation coil and the winding of the detection coil around the above-described winding frame is employed. That is, it is necessary to repeat the work of winding the winding of the excitation coil, and then winding the winding of the detection coil in a direction intersecting the excitation coil.

[PTL 1] Japanese Patent No. 6288640

However, in a case where the cross coil is manufactured using the above-described winding frame, it is difficult to automate the work, and problems arise such as an increase in cost required for manufacturing and an increase in manufacturing period. In particular, in a case of creating an array probe for eddy current testing that requires a large number of cross coils, the period required for manufacturing the cross coils has become a significant bottleneck.

The present disclosure has been made to solve the above-described problems, and an object of the present disclosure is to provide a coil module, an array probe, and an eddy current testing device that can be manufactured at a low cost and in a short time.

In order to solve the above-described problem, according to the present disclosure, there is provided a coil module including: a cross coil that includes a first coil having an annular shape centered on a first axis line, and a second coil having an annular shape centered on a second axis line intersecting the first axis line and covering a part of an outer peripheral side of the first coil; and a case that includes a first insertion point extending in a first axis line direction and into which the first coil is inserted and a second insertion point extending in a second axis line direction and into which the second coil is inserted.

According to the present disclosure, there is provided an array probe including: a plurality of the coil modules that are arranged in a first arrangement direction intersecting the first axis line and the second axis line and extending in the same plane; and a holding member that supports the plurality of coil modules and is formed of an elastically deformable material.

According to the present disclosure, there is provided an eddy current testing device including: the array probe; a power supply unit that supplies an alternating current to each of the first coil and the second coil; and a switch unit that switches a supply state of the alternating current between a mutual induction standard comparison method in which one of the first coil and the second coil operates as an excitation coil that generates an eddy current and the other operates as a detection coil that detects a flaw due to a disturbance of the eddy current, and a self-induction self-comparison method in which each of the first coil and the second coil operates as the excitation coil that generates the eddy current and as the detection coil that detects the flaw due to the disturbance of the eddy current.

According to the present disclosure, it is possible to provide a coil module, an array probe, and an eddy current testing device that can be manufactured at a low cost and in a short time.

1 10 20 1 7 FIGS.to Hereinafter, an eddy current testing device, an array probe, and a coil moduleaccording to an embodiment of the present disclosure will be described with reference to.

1 The eddy current testing deviceis a device for detecting a defect (cracks or thinning) generated in a target object by scanning along the surface of the target object, for example, in a butt weld portion or a fillet weld portion of a plant member and a straight pipe portion or an elbow portion of a pipe in nuclear power plant.

1 FIG. 1 10 30 40 50 As shown in, the eddy current testing deviceincludes the array probe, a switch unit, a power supply unit, and a data acquisition unit main body.

10 40 10 20 10 20 10 50 30 20 20 30 The array probeis used, for example, by being disposed on a weld portion and scanning the weld portion. The power supply unitapplies an alternating current voltage to the array probe, and generates an alternating current in the coil modulewhich will be described later. By scanning the array probealong the surface of the weld portion or the like, a disturbance occurs in the eddy current generated from the coil modulein a case where the array probepasses through a defective part. The data acquisition unit main bodyis a device that converts the disturbance of the eddy current into a numerical value or an image and visually transmits the result to an operator. The switch unitis a device that switches a supply state of an alternating current flowing through the coil module(a method for excitation and detection in the coil constituting the coil module). The switching of the operation method by means of the switch unitwill be described later.

2 FIG. 2 FIG. 10 60 60 1 60 2 1 As shown in, the array probehas a plurality of probe columns. Each probe columnextends in a first arrangement direction D. The plurality of probe columnsare arranged closely together in a second arrangement direction Dorthogonal to the first arrangement direction Dwith a plurality of columns (four in the example of).

60 20 11 20 20 1 11 20 20 11 11 11 The probe columnhas a plurality of coil modulesand a holding memberthat holds the coil modules. The coil modulesare arranged in a plurality of rows at small intervals in the first arrangement direction D. The holding memberholds the plurality of coil modulesarranged in this manner in a state in which the postures and the arrangement positions of the plurality of coil modulesare maintained. The holding memberis integrally formed of a resin material that is easily elastically deformable, such as an elastomer or polyvinyl chloride. That is, the holding membercan conform closely to a curved surface of, for example, a pipe or a weld portion without a gap by being pressed from the outside. In addition, in a case where the pressing force is released, it is possible to restore the shape to the initial shape due to the elastic restoring force. In other words, the holding memberhas flexibility.

12 3 1 2 11 12 3 12 1 12 20 12 12 20 12 20 12 20 1 60 2 20 1 60 20 20 A plurality of insertion pointsrecessed in a direction (a third axis line Adirection, which will be described later) orthogonal to the first arrangement direction Dand the second arrangement direction Dare formed in the holding member(bottom portions of the insertion pointsin the third axis line Adirection may be penetrated). The insertion pointsare arranged in the first arrangement direction Dat small intervals. The insertion pointhas an octagonal opening shape. The coil moduleis fitted into the insertion point. More specifically, an inner surface of the insertion pointis elastically deformed by pushing the coil moduleinto the insertion point, and the coil moduleis held within the insertion pointby a restoring force based on the elastic deformation. Further, the positions of the coil modulesin the first arrangement direction Dare different from each other in a pair of probe columnsadjacent to each other in the second arrangement direction D. That is, the positions of the coil modulesin the first arrangement direction Dare slightly deviated for each probe column, so that the gaps between the coil modulesare covered. This is to prevent overlooking of defective parts due to the occurrence of gaps between the coil modules.

1 2 FIGS.and 60 11 11 60 In, although an example in which the probe columnsof the holding memberare divided into a plurality of pieces is shown, the embodiment is not limited to this, and one holding membercan also be configured by a plurality of probe columnsformed integrally.

3 FIG. 20 21 22 21 71 72 71 1 72 2 1 72 71 71 72 As shown in, the coil modulehas a cross coiland a case. The cross coilhas a first coiland a second coil. The first coilhas a rectangular annular shape centered on a first axis line A. The second coilhas a rectangular annular shape centered on a second axis line Aorthogonal to the first axis line A. An inner opening dimension of the second coilis set to be the same as or slightly larger than an outer dimension of the first coil. That is, the first coilis in a state of being inserted into the inner opening of the second coil.

71 72 1 2 71 72 22 71 72 Desirably, the first coiland the second coilare orthogonal to each other at a center portion in the first axis line Adirection and the second axis line Adirection. However, even in a case where the central portions of the first coiland the second coilare slightly deviated, the detection accuracy is not affected or is only slightly affected. Therefore, the dimensional accuracy of the case, which will be described later, may also include a manufacturing error that is large enough to allow for such a deviation. In addition, the shapes of the first coiland the second coilare not limited to a rectangular annular shape, and may be a circular annular shape.

22 21 21 22 81 82 71 81 72 82 81 2 3 1 2 3 81 71 81 2 71 81 1 71 1 81 3 71 3 71 81 3 71 4 FIG. The caseis a member for maintaining the shape and the posture of the cross coilby holding the cross coilfrom the outer side. The casehas a first insertion pointand a second insertion point. The first coilis inserted into the first insertion point, and the second coilis inserted into the second insertion point. As shown in, the first insertion pointis a groove that extends in the second axis line Adirection and is recessed in the third axis line Adirection orthogonal to the first axis line Aand the second axis line A. In a case of being viewed from the third axis line Adirection, the first insertion pointhas a rectangular shape corresponding to a projection shape of the first coil. The dimension of the first insertion pointin the second axis line Adirection is set to be the same as or slightly larger than the dimension of the first coil. The dimension of the first insertion pointin the first axis line Adirection is set to be the same as or slightly larger than the dimension of the first coilin the first axis line Adirection. The dimension of the first insertion pointin the third axis line Adirection is set to be larger than the dimension of the first coilin the third axis line Adirection. That is, in a state in which the first coilis inserted into the first insertion point, a space is formed on one side in the third axis line Adirection of the first coil.

5 FIG. 82 1 3 3 82 72 82 1 72 82 2 72 2 82 3 72 3 72 82 3 72 As shown in, the second insertion pointis a groove that extends in the first axis line Adirection and is recessed in the third axis line Adirection. In a case of being viewed from the third axis line Adirection, the second insertion pointhas a rectangular shape corresponding to the projection shape of the second coil. The dimension of the second insertion pointin the first axis line Adirection is set to be the same as or slightly larger than the dimension of the second coil. The dimension of the second insertion pointin the second axis line Adirection is set to be the same as or slightly larger than the dimension of the second coilin the second axis line Adirection. The dimension of the second insertion pointin the third axis line Adirection is set to be larger than the dimension of the second coilin the third axis line Adirection. That is, in a state in which the second coilis inserted into the second insertion point, a space is formed on one side in the third axis line Adirection of the second coil.

4 FIG. 83 82 84 81 3 3 84 83 72 71 85 83 72 2 72 83 85 In addition, as shown in, a bottom surface (second bottom surface) of the second insertion pointis recessed from a bottom surface (first bottom surface) of the first insertion pointin the third axis line Adirection. More specifically, the dimension in the third axis line Adirection from the first bottom surfaceto the second bottom surfaceis set to be the same as or slightly larger than the protruding dimension of the second coilwith respect to the first coil. In addition, a distance dimension between a pair of surfaces (side surfaces) facing each other with the second bottom surfaceinterposed therebetween is the same as or slightly larger than the dimension of the second coilin the second axis line Adirection. A part of the second coilis surrounded by the second bottom surfaceand the pair of side surfacesto be supported and fixed.

3 FIG. 22 3 91 22 1 1 91 22 2 2 22 3 22 3 22 11 22 3 As shown in, the casehas an octagonal shape as viewed from the third axis line Adirection. More specifically, end surfacesof the caseon both sides in the first axis line Adirection extend in a plane orthogonal to the first axis line A. In addition, end surfacesof the caseon both sides in the second axis line Adirection extend in a plane orthogonal to the second axis line A. It is desirable that the respective end edges of the caseas viewed from the third axis line Adirection have the same dimensions. That is, it is desirable that the casehas a regular octagonal shape as viewed from the third axis line Adirection. Meanwhile, in order to prevent the erroneous recognition of the posture of the case, a configuration in which the lengths of a pair of end edges adjacent to each other are different can also be adopted. In addition, in order to maximize the flexibility of the holding member, the casecan also be configured to have a circular shape as viewed from the third axis line Adirection.

20 20 30 6 7 FIGS.and Next, an operation method of the coil modulewill be described with reference to. In the coil module, two operating methods are selectable: the “mutual induction standard comparison method” and the “self-induction self-comparison method.” The switching between these two methods is performed by appropriately changing a connection state of the wiring in the switch unit.

71 72 72 71 1 1 100 6 FIG. 6 FIG. 6 FIG. In the mutual induction standard comparison method, one of the first coiland the second coilis used as an excitation coil, and the other is used as a detection coil. The excitation coil generates eddy currents on a surface of the inspection site including the weld portion or the like. In a case where the crack or thinning occurs in the weld portion or the like, the disturbance occurs in the eddy current. The detection coil detects the disturbance of the eddy current.shows a case where the second coilis used as the excitation coil and the first coilis used as the detection coil, as an example. As indicated by arrows in, the eddy currents form a plurality of arc shapes extending from one end side to the other end side in the first axis line Adirection on the surface of the inspection site. In this case, the detection accuracy of flaws or cracks extending in a direction crossing the eddy current is improved. Meanwhile, for example, the detection accuracy of the flaw or the crack in the first axis line Adirection indicated by a dotted lineinis reduced.

71 72 1 2 3 1 2 7 FIG. In the self-induction self-comparison method, each of the first coiland the second coiloperates as the excitation coil and also operates as the detection coil at the same time. That is, the method is a method of detecting the disturbance in the eddy current by oneself based on the eddy current generated by oneself. In this case, as shown in, the eddy currents flow in a plurality of arc shapes from one end side to the other end side in a direction intersecting the first axis line Adirection and the second axis line Adirection at 45° as viewed from the third axis line Adirection. As a result, it is possible to ensure the detection accuracy of flaws or cracks extending in the first axis line Adirection or the second axis line Adirection, which are difficult to detect using the above-described mutual induction standard comparison method.

1 1 40 20 10 30 10 20 50 50 Next, an example of a method of using the eddy current testing deviceand the probe array, which are above-described, will be described. In a case where the eddy current testing deviceis used, first, the power supply unitsupplies an alternating current to each coil moduleof the array probe. In addition, the switch unitappropriately selects any one of the two operation methods described above. In this state, the array probeis scanned along the surface of the pipe, the weld portion, or the like. In a case where the respective coil modulesdetect a defective part, the data acquisition unit main bodyspecifies a position of the defect and checks the properties such as the depth and the length. More specifically, a position is specified by an encoder in the data acquisition unit main body, and the properties such as the depth and the length are acquired by analysis.

21 Here, in the related art, a method of alternately winding the winding of the excitation coil and the winding of the detection coil around the above-described winding frame has been adopted in order to manufacture the cross coil. That is, it is necessary to repeat the work of winding the winding of the excitation coil, and then winding the winding of the detection coil in a direction intersecting the excitation coil.

21 21 21 However, in a case where the cross coilis manufactured using the above-described winding frame, it is difficult to automate the work, and problems arise such as an increase in cost required for manufacturing and an increase in manufacturing period. In particular, in a case of creating a probe for eddy current testing that requires a large number of cross coils, the delivery time of the cross coilshas become a significant bottleneck. Therefore, each of the above-described configurations is adopted in the present embodiment.

20 71 72 21 21 81 82 22 According to the above-described configuration, the coil modulecan be easily manufactured by inserting the first coilinto the inside of the second coilto assemble the cross coil, and then inserting the cross coilinto the first insertion pointand the second insertion pointof the case. In addition, a large number of coils having a simple annular shape can be manufactured at low cost and in a short delivery time through automation. Accordingly, it is not necessary to perform the work of alternately winding the winding around the winding frame as in the related art. As a result, it is possible to achieve both a significant reduction in manufacturing cost and a reduction in the period required for manufacturing.

81 82 3 21 22 21 21 22 21 Further, according to the above-described configuration, since the first insertion pointand the second insertion pointare open toward one side in the third axis line Adirection, the cross coilcan be easily inserted into the casethrough the opening. Accordingly, the work procedure is significantly simplified, and the number of steps required for assembly can be reduced. In addition, the shape and the posture of the cross coilcan be stably maintained only by inserting the cross coilinto the case. Accordingly, for example, it is possible to reduce the possibility that the cross coilis damaged, deformed, or changed in posture due to an external force.

82 72 83 3 84 21 22 72 83 85 83 72 72 72 In addition, according to the above-described configuration, the second insertion pointis recessed by a height of the second coilthat protrudes to an outer peripheral side. That is, the second bottom surfaceis located at a position recessed in the third axis line Adirection with respect to the first bottom surface. Accordingly, in a state in which the cross coilis inserted into the case, the second coilis surrounded by the second bottom surfaceand the pair of side surfacesinterposing the second bottom surfacetherebetween. Therefore, the position of the second coilis defined, and the possibility of occurrence of rattling or deviation of the posture of the second coilcan be reduced. As a result, in a case where the flaw detection work is performed, it is possible to significantly reduce the occurrence of noise caused by the rattling of the second coil. Accordingly, it is possible to improve the accuracy and efficiency of the flaw detection work.

71 72 71 72 20 Further, according to the above-described configuration, since the first coiland the second coileach have a rectangular annular shape, the area (facing area) of the region close to the flaw detection object, such as the pipe or the weld portion, can be increased, for example, as compared with a case where the first coiland the second coilhave a circular annular shape. Accordingly, it is possible to generate eddy currents in a wider range and to detect the disturbance of the eddy currents in a wider range. Meanwhile, in a case where each coil has a circular annular shape, a region close to a pipe or the like is narrowed. As a result, since the region where the eddy current is generated is limited, the intensity of the eddy current is also reduced, and the defect detection properties of flaws and thinning are deteriorated. According to the above-described configuration, since such a disadvantage is eliminated, the flaw detection accuracy can be significantly improved in a case where the coil moduleis applied to the flaw detection device.

10 11 11 11 11 10 20 In addition, according to the above-described configuration, the array probehas an elastically deformable holding member. In other words, the holding memberhas flexibility. That is, by pressing the holding memberagainst the curved surface of the pipe or the like, the holding memberis elastically deformed, and the entire array probecan be brought into close contact with the curved surface. In this state, by performing the scanning with the coil module, it is possible to prevent the coil from floating in a region where the shape changes, such as the surface of the pipe, the elbow portion of the pipe, or the surface of the weld portion, and it is possible to ensure the defect detection property,

20 12 11 20 20 12 10 In addition, according to the above-described configuration, the coil moduleis inserted one by one into each insertion pointformed in the holding member. Accordingly, for example, in a case where any coil modulebecomes defective, only the coil modulein which the defect has occurred can be taken out from the insertion pointand can be immediately replaced with a new one. Accordingly, it is possible to reduce the maintenance cost and the operation cost of the array probe.

60 1 20 20 2 10 2 1 20 In addition, according to the above-described configuration, since the positions of the probe columnsin the first arrangement direction Dof the coil moduleare different from each other, the coil modulesoverlap each other and there is no gap in a case of being viewed from the second arrangement direction D. Accordingly, in a case where the array probeis moved in the second arrangement direction D, a wider range in the first arrangement direction Dis covered by each coil module. Accordingly, it is possible to uniformly scan the pipe, the weld portion, and the like over a wider range under a higher detection density.

91 1 91 2 22 3 11 10 22 10 10 10 10 10 In addition, according to the above-described configuration, the end surfacesfacing both sides in the first axis line Adirection and the end surfacesfacing both sides in the second axis line Adirection are chamfered. That is, the casegenerates an octagonal shape as viewed from the third axis line Adirection. Accordingly, in a case where the holding memberof the array probeis elastically deformed, the corners of the casedo not interfere with each other. In particular, in a case where the array probeitself is elastically deformed to be twisted, the corners do not interfere with each other, and thus the change in the shape of the array probeis less likely to be hindered. Therefore, the ability of the array probeto conform to the curved surface can be further improved. Accordingly, the array probecan be applied to various curved surface shapes, and the general-purpose properties of the array probecan be improved.

1 30 71 72 71 72 10 Further, according to the above-described configuration, since the eddy current testing deviceincludes the switch unit, the operation method of each of the first coiland the second coilcan be switched. Accordingly, it is possible to change the direction in which the eddy current flows without changing the postures of the first coiland the second coil. That is, it is possible to generate the eddy currents in various directions using the same array probe. By changing the direction of the eddy current according to the direction of the defective part (crack or thinning) of the pipe, the weld portion, or the like, it is possible to perform scanning and flaw detection with higher density and higher accuracy in response to various defective parts.

Although the embodiment of the present disclosure has been described in detail above with reference to the drawings, the specific configuration of the present disclosure is not limited to the embodiment, and the present disclosure includes design changes or the like without departing from the scope of the present disclosure.

71 72 21 21 71 72 71 72 21 8 FIG. 9 FIG. For example, in the above-described embodiment, an example in which the first coiland the second coilof the cross coileach have a rectangular annular shape has been described. However, the shape of the cross coilis not limited to the above. As shown inas a first modification example, the first coilcan be formed in a circular annular shape and the second coilcan be formed in a rectangular annular shape. In addition, as shown inas a second modification example, both the first coiland the second coilcan be formed in a circular annular shape. While either case can be applied to the cross coil, the shape described in the above embodiment is most advantageous in terms of the detection accuracy of defective parts.

20 10 1 20 21 71 1 72 2 1 71 22 81 1 71 82 2 72 (1) A coil moduleaccording to a first aspect includes a cross coilthat includes a first coilhaving an annular shape centered on a first axis line A, and a second coilhaving an annular shape centered on a second axis line Aintersecting the first axis line Aand covering a part of an outer peripheral side of the first coil. and a casethat includes a first insertion pointextending in a first axis line Adirection and into which the first coilis inserted and a second insertion pointextending in a second axis line Adirection and into which the second coilis inserted. The coil module, the array probe, and the eddy current testing devicedescribed in each embodiment are understood, for example, as follows.

20 71 72 21 81 82 22 20 20 81 82 3 1 2 (2) A coil moduleaccording to a second aspect is the coil moduleaccording to the first aspect, in which the first insertion pointand the second insertion pointare open toward one side in a third axis line Adirection orthogonal to the first axis line Aand the second axis line A. According to the above-described configuration, the coil modulecan be easily manufactured by inserting the first coilinto the inside of the second coilto assemble the cross coil, and then inserting it into the first insertion pointand the second insertion pointof the case. Accordingly, it is possible to achieve both reduction in manufacturing cost and shortening of delivery time.

81 82 3 21 22 20 20 82 3 81 72 3 (3) A coil moduleaccording to a third aspect is the coil moduleaccording to the second aspect, in which a bottom surface of the second insertion pointis recessed in the third axis line Adirection from a bottom surface of the first insertion pointby a height of the second coilin the third axis line Adirection. According to the above-described configuration, since the first insertion pointand the second insertion pointare open toward one side in the third axis line Adirection, the cross coilcan be easily inserted into the casethrough the opening. Accordingly, the number of steps required for assembly can be reduced.

82 72 72 21 22 20 20 71 1 72 2 (4) A coil moduleaccording to a fourth aspect is the coil moduleaccording to any one of the first to third aspects, in which the first coilhas a rectangular annular shape centered on the first axis line A, and the second coilhas a rectangular annular shape centered on the second axis line A. According to the above-described configuration, since the second insertion pointis recessed by the height of the second coilprotruding to the outer peripheral side, it is possible to reduce the possibility of occurrence of rattling or deviation of the posture of the second coilin a state in which the cross coilis inserted into the case.

71 72 71 72 20 10 20 1 1 2 11 20 (5) An array probeaccording to a fifth aspect includes a plurality of the coil modulesaccording to any one of the first to fourth aspects that are arranged in a first arrangement direction Dintersecting the first axis line Aand the second axis line Aand extending in the same plane, and a holding memberthat supports the plurality of coil modulesand is formed of an elastically deformable material. According to the above-described configuration, since the first coiland the second coileach have a rectangular annular shape, the area (facing area) of the region close to the flaw detection object, such as the pipe or the weld portion, can be increased, for example, as compared with a case where the first coiland the second coilhave a circular annular shape. As a result, it is possible to improve the flaw detection accuracy in a case where the coil moduleis applied to the flaw detection device.

11 11 10 20 10 10 11 12 20 (6) An array probeaccording to a sixth aspect is the array probeaccording to the fifth aspect, in which the holding memberhas a plurality of insertion pointsinto which the coil modulesare inserted. According to the above-described configuration, by pressing the holding memberagainst the curved surface of the pipe, the weld portion, or the like, the holding memberis elastically deformed, and the entire array probecan be brought into close contact with the curved surface. By performing scanning with the coil modulein this state, it is possible to perform the flaw detection with higher accuracy.

20 12 20 20 12 10 10 10 60 2 1 20 11 60 2 20 1 (7) An array probeaccording to a seventh aspect is the array probeaccording to the fifth or sixth aspect, and has a plurality of probe columnsarranged in a second arrangement direction Dorthogonal to the first arrangement direction Dtogether with the plurality of the coil modulesand the holding member, and in a pair of the probe columnsadjacent to each other in the second arrangement direction D, positions of the coil modulesin the first arrangement direction Dare different from each other. According to the above-described configuration, since the coil modulesare inserted one by one into each insertion point, for example, in a case where any coil modulebecomes defective, only the coil modulein which the defect has occurred can be taken out from the insertion pointand can be immediately replaced with a new one. Accordingly, it is possible to reduce the maintenance cost and the operation cost of the array probe.

60 1 20 20 2 20 1 10 10 91 1 1 91 2 2 22 (8) An array probeaccording to an eighth aspect is the array probeaccording to any one of the fifth to seventh aspects, in which an end surfacefacing both sides in the first axis line Adirection extends in a plane intersecting the first axis line A, and an end surfacefacing both sides in the second axis line Adirection extends in a plane intersecting the second axis line A, in the case. According to the above-described configuration, since the positions of the probe columnsin the first arrangement direction Dof the coil moduleare different from each other, the coil modulesoverlap each other and there is no gap in a case of being viewed from the second arrangement direction D. Accordingly, the coil modulecan scan the weld portion, the pipe, and the like without floating over a wider range in the first arrangement direction D.

91 1 91 2 22 3 11 10 22 10 1 10 40 71 72 30 71 72 71 72 (9) An eddy current testing deviceaccording to a ninth aspect includes the array probeaccording to any one of the fifth to eighth aspects, a power supply unitthat supplies an alternating current to each of the first coiland the second coil, and a switch unitthat switches a supply state of the alternating current between a mutual induction standard comparison method in which one of the first coiland the second coiloperates as an excitation coil that generates an eddy current and the other operates as a detection coil that detects a flaw due to a disturbance of the eddy current, and a self-induction self-comparison method in which each of the first coiland the second coiloperates as the excitation coil that generates the eddy current and as the detection coil that detects the flaw due to the disturbance of the eddy current. According to the above-described configuration, the end surfacesfacing both sides in the first axis line Adirection and the end surfacesfacing both sides in the second axis line Adirection are chamfered. That is, the casegenerates an octagonal shape as viewed from the third axis line Adirection. Accordingly, in a case where the holding memberof the array probeis elastically deformed, the corners of the casedo not interfere with each other. Therefore, the ability of the array probeto conform to the curved surface can be further improved.

30 71 72 71 72 According to the above-described configuration, since the switch unitis included, the operation method of each of the first coiland the second coilcan be switched. Accordingly, it is possible to change the direction in which the eddy current flows without changing the postures of the first coiland the second coil. By changing the direction of the eddy current according to the direction of the defective part (crack or thinning) of the pipe, the weld portion, or the like, it is possible to perform scanning and flaw detection in response to various defective parts.

The present disclosure relates to a coil module, an array probe, and an eddy current testing device that can be manufactured at a low cost and in a short time.

1 : eddy current testing device 10 : array probe 11 : holding member 12 : insertion point 20 : coil module 21 : cross coil 22 : case 30 : switch unit 40 : power supply unit 50 : data acquisition unit main body 60 : probe column 71 : first coil 72 : second coil 81 : first insertion point 82 : second insertion point 83 : second bottom surface 84 : first bottom surface 85 : side surface 91 : end surface 100 : dotted line 1 A: first axis line 2 A: second axis line 3 A: third axis line 1 D: first arrangement direction 2 D: second arrangement direction